The interrelationship between malnutrition and heart disease is poorly understood. A series of preliminary experiments performed in this laboratory using a cannine model of adult marasmus (protein-calorie malnutrition) successfully determined that the induction of malnutrition on a subacute basis resulted in the following changes compared with a match set of control animals: decrease in precise measurements of heart contractility, increase in water content of the heart, electron microscopic changes consistent with injury to the heart muscle. It is the purpose of continued experiments in this area to complete the determination of the precise effects of this nutritional intervention, namely, the biochemical effects on heart muscle of the production of starvation and the effects on protein structure itself. Future planned experiments would, therefore include production of protein calorie malnutrition in matched dogs followed by a period of re-feeding on the one hand only carbohydrate in fat to correct a caloric imbalance but not to correct protein inefficiency and, on the other hand to feed a hypocaloric diet of just protein in an attempt to separate the causes of the ddlatorius effects on heart structure and function.